Solar energy is a long (1)..... source of energy which can be used(2).... anywhere. To generate solar energy, we only need solar cells and the sun! Solar cells can be easily be(3).... on house roofs, so no new space is(4).... and each user can quietly generate their own energy. (5)... to other renewable sources, they also possess many advantages. Wind and water power rely on turbines which are noisy, expensive and easy to break down. Solar cells are totally silent and no-polluting. As they have no moving parts, they require little maintenance and have (6)..... lifetime. However, solar energy also has some disadvantages. We can only generate solar energy during (7)..... because the system depend on sunlight. Beside solar cells require(8)... area to work effectively. The main disadvantage of solar energy is that it costs(9).... twice as much as traditional sources such as coal, oil, and gas. This is because solar cells are(10)... . Scientists are hoping that the costs of solar cells will reduce as more and more people see the advantages of the environmentally(11)..... source of energy.